The Standard Error for the Difference in Means If Two $\sqrt { \frac { s _ { M } ^ { 2 } + s _ { W } ^ { 2 } } { n _ { M } + n _ { W } } }$

Short Answer

The standard error for the difference in means if two random variables M and W , when the two population variances are different, is a. $\sqrt { \frac { s _ { M } ^ { 2 } + s _ { W } ^ { 2 } } { n _ { M } + n _ { W } } }$ .

b. $\frac { s _ { M } } { n _ { M } } + \frac { s _ { W } } { n _ { W } }$ .

c. $\sqrt { \frac { 1 } { 2 } \left( \frac { s _ { M } ^ { 2 } } { n _ { M } } + \frac { s _ { W } ^ { 2 } } { n _ { W } } \right) }$ .

d. $\sqrt { \frac { s _ { M } ^ { 2 } } { n _ { M } } + \frac { s _ { W } ^ { 2 } } { n _ { W } } }$ .